Various enclosures, whether they are sealed, substantially sealed, or unsealed to their surrounding environment are cooled. Typically, the enclosures house various components that may be adversely affected by temperatures elevated above room or ambient temperature. In the case of enclosures containing electrical equipment, heat buildup within the enclosures can damage the components and/or cause safety hazards, for example, fires. Many of these enclosures, particularly those that are substantially or completely sealed, are not easily ventilated.
U.S. Pat. No. 3,654,768, entitled “Vortex Tube Cooling System” (the “'768 patent”) which is hereby incorporated by reference in its entirety, discloses a cooling system particularly adapted for various types of enclosures, including sealed, substantially sealed, and unsealed enclosures. The system disclosed in the '768 patent is a vortex tube cooling system that includes a mechanical thermostat operable to actuate a valve that controls the flow of compressed air to the vortex tube, which, in turn, controls the temperature inside the enclosure. The embodiments described in the '768 patent provide a relatively small, thermostatically controlled cooling system that is easy to install and requires relatively low maintenance, when compared to conventional “Freon type” air conditioners. The systems disclosed in the '768 patent, however, provide a cooling system that produces high noise levels. In particular, the noise created by the high velocity spinning air within a vortex tube may be objectionable to some. Such noise may annoy, irritate, or even cause discomfort to, an operator of the enclosure, or those in close proximity to the enclosure.
Previous attempts at minimizing noises produced by the vortex tube include attaching mufflers to the hot and cold ends of the vortex tube. The mufflers, however, do not substantially reduce the noise levels a significant amount.
Thus, a need exists for compact cooling system that is easy to install and produces low noise levels.